Method for the transfer of thin layers monocrystalline material onto a desirable substrate

A method for the transfer of an upper portion of a monocrystalline, first substrate to a second substrate, said first substrate consisting of said upper portion and a lower portion, said lower portion constituting a majority of said first substrate and said upper portion having a surface which is essentially flat, said method consisting of the steps of:

• subjecting said surface to a hydrogen implantation at a hydrogen implantation temperature above room temperature, said hydrogen implantation having a dose, wherein said hydrogen implantation temperature is greater than 150 degrees centigrade but less than above 250 degrees centigrade and said hydrogen implantation dose is less than 5.times.10.sup.17 cm.sup.-2, said hydrogen selected from the group consisting of normal hydrogen and deuterium, said hydrogen having a hydrogen concentration depth distribution in said first substrate, said hydrogen concentration depth distribution having a hydrogen concentration maximum, said depth concentration maximum essentially dividing said first substrate into said upper portion and said lower portion said hydrogen implantation being shorter in duration than that required to produce hydrogen-induced surface blisters,
• bonding said surface of said first substrate to said second substrate to form a bonded structure, said bonding selected from the group consisting of direct bonding and anodic bonding;
• subjecting said bonded structure to a transfer heat-treatment treatment, said transfer heat-treatment treatment being carried out at a temperature which is less than said hydrogen implantation temperature for a sufficiently long time to grow hydrogen induced microcracks which overlap in a region adjacent to said maximum in said hydrogen concentration depth distribution which are essentially parallel to said surface, whereby said upper portion of said first substrate is separated by splitting from said lower portion and transferred to said second substrate.

A method for transferring an upper portion of a monocrystalline, first substrate to a second substrate, said method providing both a reduced level of hydrogen implantation dose requirement and a reduced splitting temperature requirement, said first substrate consisting of said upper portion and a lower portion, said lower portion constituting a majority of said first substrate and said upper portion having a surface which is essentially flat, said method consisting of the steps of:

• subjecting said surface to a hydrogen trap-inducing implantation of one or more elements, said one or more elements selected from that group consisting of boron, aluminum, gallium, indium, and thallium, said at least one element having an element depth distribution after implantation in said first substrate, said element depth distribution having an element concentration maximum, said element concentration maximum essentially dividing said first substrate into said upper portion and said lower portion, said hydrogen trap-inducing implantation having a dose less than 5.times.10.sup.16 per square centimeter but greater than 1.times.10.sup.10 per square centimeter, said hydrogen trap-inducing implantation being carried out in conjunction with hydrogen implantation;
• subjecting said surface to a hydrogen implantation of less than 5.times.10.sup.17 cm.sup.-2 at a hydrogen implantation temperature, wherein said hydrogen implantation temperature is above 150.degree. C. but below 1200.degree. C., said hydrogen selected from that group consisting of normal hydrogen and deuterium, said hydrogen having a hydrogen depth distribution in said first substrate, said hydrogen distribution having a hydrogen concentration maximum, said hydrogen concentration maximum occurring essentially at said element concentration maximum, said hydrogen implantation being shorter in duration than that required to produce hydrogen-induced surface blisters, said hydrogen implantation being carried out in conjunction with hydrogen trap-inducing implantation;
• subjecting said first substrate to a sensitizing heat-treatment at a sensitizing temperature below that temperature at which implantation-induced hydrogen-traps are annealed, for a time sufficient to form microscopic, sub-surface microcracks essentially at said hydrogen concentration maximum and parallel to said surface but shorter than that required to produce hydrogen-induced surface blisters;
• bonding said surface of said first substrate to said second substrate to form a bonded structure by a bonding method chosen from anodic bonding and direct wafer bonding;
• subjecting said bonded structure to a transfer heat-treatment at a transfer temperature, for a time sufficiently long to grow hydrogen induced microcracks which overlap in a region adjacent to said maximum in said hydrogen concentration distribution and which are essentially parallel to said surface, whereby said upper portion of said first substrate is separated by splitting from said lower portion and transferred to said second substrate.